"20/20" INVESTIGATES UNKNOWN DETAILS OF AMERICAN STUDENT'S DEATH AFTER BEING DETAINED IN NORTH KOREA FOR 17 MONTHS

"20/20" Airs Friday, June 23 on ABC

While attempting to leave North Korea after a five-day trip with Young Pioneer Tours, 21-year-old Otto Warmbier was accused of trying to steal a propaganda poster from his hotel and disappeared. Weeks after his arrest in March 2016, North Korean officials sentenced Otto to 15 years of hard labor for a "hostile act" against the state. After 17 months in prison, American officials were allowed to travel to North Korea to bring him home. Otto returned to the United States on June 13 in a state of unresponsive wakefulness and passed away on June 19. The cause of Otto's medical condition and the details of his imprisonment are currently unknown. David Muir anchors "20/20" FRIDAY, JUNE 23 (10:00-11:00 p.m., ET) on ABC.

"20/20" travels across the world searching for answers, speaking to friends, experts and others who have been to North Korea about Otto's life and what he may have experienced while in detention. The hour includes interviews with Kenneth Bae, a former North Korean detainee, and others who have been on Young Pioneer tours.

Three weeks after arresting Otto in the Pyongyang Sunan International Airport, North Korean officials announced that they were holding the University of Virginia student, later releasing a video that showed Otto purportedly confessing to his crime. During his detention United States officials made multiple attempts to bring Otto home but were unsuccessful. Then, in early June, State Department Special Representative Joseph Yun was informed of Otto's medical condition and was allowed to bring him back to the United States.

"20/20" is anchored by Elizabeth Vargas and David Muir. David Sloan is senior executive producer.